Tilt Test Duration in Suspected Vasovagal Syncope: Temporal Patterns and Diagnostic Yield in Patients From Central...

The head-up tilt test (HUTT) diagnoses Vasovagal Syncope (VVS) but its duration limits adoption. We evaluated a shortened HUTT protocol in patients from Central China.

We retrospectively analyzed 614 patients (median age 53.5 years, 53.2% female) with suspected VVS. All underwent a standardized HUTT with a 10 min passive phase at 70°, followed, if negative, by a 15 min active phase with 0.5 mg sublingual nitroglycerin. The overall positivity rate was 60.91% (374/614), with the vast majority (359/374) of positive responses occurring during the active phase. The median positive response time was 10 min (IQR: 6.5-10) for the passive phase and 3 min (IQR: 2-5min) for the active phase, with peak incidences observed at these intervals. The positivity rates for the 10 min and 15 min active phases were 58.63% and 60.91%, respectively, with no statistically significant difference (p = 0.449). Through generalized additive model (GAM) analysis with inflection point detection, a significant nonlinear relationship between time and positivity was identified (EDF = 2.302, p < 0.001). Independent predictors of a positive test included female gender, increasing age, prior syncope before HUTT, and lower systolic blood pressure at 10 min of the passive phase.

Our shortened HUTT protocol achieved comparable diagnostic yield in these patients while reducing test duration. Compared with the consensus-recommended protocol, the shortened HUTT protocol saved at least 37.5% of the total test time, while achieving a positive rate (60.91%).